Describing Distribution

Front

What does it mean if a distribution is skewed right?

Back

A distribution is skewed right if it has a longer tail on the right side, indicating that there are a few high values pulling the mean to the right.

Front

What is the definition of a normal distribution?

Back

A normal distribution is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Front

What percentage of data falls within one standard deviation of the mean in a normal distribution?

Back

Approximately 68% of the data falls within one standard deviation of the mean.

Front

What is the empirical rule in statistics?

Back

The empirical rule states that for a normal distribution: about 68% of data falls within one standard deviation, 95% within two standard deviations, and 99.7% within three standard deviations.

Front

How do you calculate the z-score?

Back

The z-score is calculated using the formula: z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

What does a z-score tell you?

Back

A z-score indicates how many standard deviations an element is from the mean. A positive z-score indicates a value above the mean, while a negative z-score indicates a value below the mean.

Front

What is the significance of the mean in a data set?

Back

The mean is the average of a data set and is a measure of central tendency that summarizes the data.

Front

What does it mean if a distribution is symmetrical?

Back

A symmetrical distribution is one where the left and right sides of the distribution are mirror images of each other, indicating that the mean, median, and mode are all equal.

Front

What is a histogram?

Back

A histogram is a graphical representation of the distribution of numerical data, showing the frequency of data points within specified ranges (bins).

Front

What does it mean if a distribution is skewed left?

Back

A distribution is skewed left if it has a longer tail on the left side, indicating that there are a few low values pulling the mean to the left.